Don’t bring your gun. They are not allowed here. If you are mugged, as you almost certainly will be, pretend you don’t speak English. The police will take about 40 minutes to arrive, so try to keep them talking.

No doubt you will travel on the London Underground (it’s filthy, and the terrorists are going to blow it up any day now, but most visitors end up using it). Before you sit down, you should shake hands with everybody in the carriage. They will think you are rude if you do not. And at the end of cinema performances remember to stand up and sing God Save the Queen. Otherwise you could be arrested.

If you go south of the river, the Queen’s Law no longer runs. It is a war of each against all, nature red in tooth and claw. Don’t go south of the river.

It is September so winter is setting in hard. The blizzard season is just beginning. Don’t forget your fur hat. ("The English winter, ending in July, to recommence in August..." -Lord Byron.)